Micro-light-emitting diode display apparatus and method of manufacturing the same

ABSTRACT

The present disclosure provides a micro-light-emitting diode display apparatus and a method of manufacturing the same. Provided is a micro-light-emitting diode (LED) display apparatus including a plurality of pixels, the micro-LED display apparatus including a driving circuit substrate, a first electrode provided on the driving circuit substrate, one or more microlight-emitting diodes (LEDs) provided on the first electrode, an insulating layer provided on the one or more micro-LEDs, a via pattern provided in the insulating layer, electrical contacts provided in the via pattern, and a second electrode provided on the electrical contacts, wherein the via pattern exposes a portion of the one or more micro-LEDs.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.17/174,934, filed Feb. 12, 2021, which claims priority to Korean PatentApplication No. 10-2020-0113203, filed on Sep. 4, 2020, in the KoreanIntellectual Property Office, the disclosure of which is incorporated byreference herein in its entirety.

BACKGROUND 1. Field

Example embodiments of the present disclosure relate to a displayapparatus including a micro-light-emitting diode (LED) and a method ofmanufacturing the display apparatus including the micro-LED.

2. Description of the Related Art

Light-emitting diodes (LEDs) have benefits such as low power consumptionand environment-friendly characteristics. Because of these benefits,industrial demand for the LEDs has increased. The LEDs are applied notonly to illumination devices or liquid crystal display (LCD) backlightunits, but also to LED display apparatuses. In other words, displayapparatuses using micro-unit LED chips have been developed. Whenmanufacturing a micro-LED display apparatus, it is necessary to transfera micro-LED onto a substrate. As a method of transferring the micro-LED,a pick and place method is frequently used. However, according to thismethod, a yield rate decreases when a size of the micro-LED decreasesand a size of a display increases.

Also, with the increased number of micro-LEDs, the need for high-speedtransfer and a reduced repair rate has increased.

SUMMARY

One or more example embodiments provide a display apparatus capable ofreducing a repair rate.

One or more example embodiments also provide a method of manufacturing adisplay apparatus capable of reducing a repair rate.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of example embodiments of the disclosure.

According to an aspect of an example embodiment, there is provided amicro-light-emitting diode (LED) display apparatus including a pluralityof pixels, the micro-LED display apparatus including a driving circuitsubstrate, a first electrode provided on the driving circuit substrate,one or more micro-light-emitting diodes (LEDs) provided on the firstelectrode, an insulating layer provided on the one or more micro-LEDs, avia pattern provided in the insulating layer, electrical contactsprovided in the via pattern, and a second electrode provided on theelectrical contacts, wherein the via pattern exposes a portion of theone or more micro-LEDs.

A thickness of the insulating layer may be greater than a thickness ofthe one or more micro-LEDs.

A thickness of each of the electrical contacts may correspond to adistance between an upper surface of the insulating layer and an uppersurface of the one or more micro-LEDs.

A pitch of the electrical contacts may be less than a width of each ofthe one or more micro-LEDs.

Each of the plurality of pixels may include a plurality of sub-pixels,and the via pattern may be provided on each of the plurality ofsub-pixels.

Each of the plurality of pixels may include a plurality of sub-pixels,and the one or more micro-LEDs may be provided on each of the pluralityof the sub-pixels.

The one or more micro-LEDs may be irregularly provided.

The one or more micro-LEDs may be connected between the first electrodeand the second electrode.

The electrical contacts may be provided in dotted patterns, stripepatterns, grid patterns, or concentric-circular patterns.

The electrical contacts and the second electrode may have a samematerial.

The micro-LED display apparatus may further include an electrode padprovided between the one or more micro-LEDs and the first electrode.

The micro-LED display apparatus may further include a color conversionlayer provided on the second electrode, the color conversion layer beingconfigured to convert a color of light emitted from the one or moremicro-LEDs.

According to another aspect of an example embodiment, there is provideda method of manufacturing a micro-light emitting diode (LED) displayapparatus including a plurality of pixels, the method includingproviding a first electrode on a driving circuit substrate, providingone or more micro-light-emitting diodes (LEDs) to the driving circuitsubstrate such that a first electrode pad of the one or more micro-LEDscontacts the first electrode, providing an insulating layer on the oneor more micro-LEDs, providing, in the insulating layer, a via patternexposing a portion of the one or more micro-LEDs, providing electricalcontacts in the via pattern, and providing a second electrode on theelectrical contacts and the insulating layer.

A thickness of the insulating layer may be greater than a thickness ofthe one or more micro-LEDs.

A thickness of each of the electrical contacts may correspond to adistance between an upper surface of the insulating layer and an uppersurface of the one or more micro-LEDs.

A pitch of the electrical contacts may be less than a width of each ofthe one or more micro-LEDs.

Each of the plurality of pixels may include a plurality of sub-pixels,and the via pattern may be provided on each of the plurality ofsub-pixels.

Each of the plurality of pixels may include a plurality of sub-pixels,and the one or more micro-LEDs may be provided on each of the pluralityof sub-pixels.

The one or more micro-LEDs may be irregularly provided.

The one or more micro-LEDs may be connected between the first electrodeand the second electrode.

The electrical contacts may be provided in dotted patterns, stripepatterns, grid patterns, or concentric-circular patterns.

A depth of the via pattern may be selectively adjusted based onadjusting an etch duration time or based on a resolution and a criticaldimension of a photosensitive material.

According to another aspect of an example embodiment, there is provideda micro-light-emitting diode (LED) display apparatus including aplurality of pixels, the micro-LED display apparatus including a drivingcircuit substrate, a first electrode provided on the driving circuitsubstrate, one or more micro-light-emitting diodes (LEDs) provided onthe first electrode, an insulating layer provided on the one or moremicro-LEDs, a via pattern provided in the insulating layer, electricalcontacts provided in the via pattern, and a second electrode provided onthe electrical contacts, wherein the electrical contacts are spacedapart from the first electrode, and wherein a thickness of each of theelectrical contacts corresponds to a distance between an upper surfaceof the insulating layer and an upper surface of the one or moremicro-LEDs

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other aspects, features, and advantages of exampleembodiments will be more apparent from the following description takenin conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic pixel diagram of a micro-light-emitting diode(LED) display apparatus according to an example embodiment;

FIG. 2 is a plan view of a micro-LED display apparatus according to anexample embodiment;

FIG. 3A is a cross-sectional view of the micro-LED display apparatus ofFIG. 2 , taken along line A-A;

FIG. 3B is a cross-sectional view of a micro-LED display apparatusaccording to another example embodiment;

FIG. 4 is a cross-sectional view of a micro-LED display apparatusaccording to another example embodiment;

FIGS. 5, 6, 7, and 8 are diagrams of examples of various layoutstructures with respect to an electrode and a micro-LED of a micro-LEDdisplay apparatus according to example embodiments;

FIGS. 9, 10, 11, and 12 are diagrams of examples of various patternstructures of an electrical contact of a micro-LED display apparatusaccording to example embodiments;

FIGS. 13, 14, and 15 are diagrams of examples of various layoutstructures of a micro-LED and an electrode of a micro-LED displayapparatus according to example embodiments;

FIGS. 16, 17, 18, 19, 20, 21, 22, 23, 24, and 25 are views fordescribing a method of manufacturing a micro-LED display apparatusaccording to an embodiment;

FIG. 26 is a schematic block diagram of an electronic device accordingto an example embodiment;

FIG. 27 illustrates an example in which a micro-LED display apparatusaccording to an example embodiment is applied to a mobile device;

FIG. 28 illustrates an example in which a micro-LED display apparatusaccording to an example embodiment is applied to a vehicle displayapparatus;

FIG. 29 illustrates an example in which a micro-LED display apparatusaccording to an example embodiment is applied to augmented reality (AR)glasses;

FIG. 30 illustrates an example in which a micro-LED display apparatusaccording to an example embodiment is applied to signage; and

FIG. 31 illustrates an example in which a micro-LED display apparatusaccording to an example embodiment is applied to a wearable display.

DETAILED DESCRIPTION

Reference will now be made in detail to example embodiments of which areillustrated in the accompanying drawings, wherein like referencenumerals refer to like elements throughout. In this regard, the exampleembodiments may have different forms and should not be construed asbeing limited to the descriptions set forth herein. Accordingly, theexample embodiments are merely described below, by referring to thefigures, to explain aspects. As used herein, the term “and/or” includesany and all combinations of one or more of the associated listed items.Expressions such as “at least one of,” when preceding a list ofelements, modify the entire list of elements and do not modify theindividual elements of the list. For example, the expression, “at leastone of a, b, and c,” should be understood as including only a, only b,only c, both a and b, both a and c, both b and c, or all of a, b, and c.

Hereinafter, a micro-light-emitting diode (LED) display apparatus and amethod of manufacturing the micro-LED display apparatus according tovarious example embodiments will be described in detail with referenceto the accompanying drawings. In the drawings, the same referencenumerals denote the same elements and the sizes of elements may beexaggerated for clarity and convenience of explanation. Although theterms first, second, etc. may be used herein to describe variouselements, these terms do not limit the components. These terms are onlyused to distinguish one element from another.

As used herein, the singular terms “a” and “an” are intended to includethe plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that when a part “includes” or“comprises” an element, unless otherwise defined, the part may furtherinclude other elements, not excluding the other elements. A size of eachelement in the drawings may be exaggerated for clarity and convenienceof explanation. Also, when a certain material layer is described asbeing on a substrate or another layer, the material layer may be on thesubstrate or the other layer by directly contacting the same, or a thirdlayer may be arranged between the material layer, and the substrate orthe other layer. Also, a material included in each of layers inembodiments to be described below is only an example and other materialsmay also be used.

Also, the terms such as “unit,” “module,” or the like used in thespecification indicate an unit, which processes at least one function ormotion, and the unit may be implemented by hardware or software, or by acombination of hardware and software.

Particular executions described in the example embodiments are examplesand do not limit the technical scope by any means. For the sake ofbrevity, conventional electronics, control systems, software developmentand other functional aspects of the systems may not be described.Furthermore, the connecting lines, or connectors shown in the variousfigures presented are intended to represent exemplary functionalrelationships and/or physical or logical couplings between the variouselements. It should be noted that many alternative or additionalfunctional relationships, physical connections or logical connectionsmay be present in a practical device.

The term “the” and other equivalent determiners may correspond to asingular referent or a plural referent.

Unless orders of operations included in a method are specificallydescribed or there are contrary descriptions, the operations may beperformed according to appropriate orders. The use of all example terms(e.g., etc.) are merely for describing the disclosure in detail and thedisclosure is not limited to the examples and the example terms, unlessthey are not defined in the scope of the claims.

FIG. 1 is a plan view of a micro-light-emitting diode (LED) displayapparatus according to an example embodiment.

Referring to FIG. 1 , the micro-LED display apparatus 100 may include aplurality of pixels 135. The plurality of pixels 135 may be arranged inthe form of a two-dimensional matrix. Each of the plurality of pixels135 may include a plurality of sub-pixels 1351, 1352, and 1353.

Each of the pixels 135 may indicate a basic unit for displaying a colorin the micro-LED display apparatus 100. For example, one pixel 135 mayemit first color light, second color light, and third color light andmay display color light via the first through third color lights. Forexample, the first color light may include red light, the second colorlight may include green light, and the third color light may includeblue light. However, the color lights are not limited thereto. Each ofthe pixels 135 may include the plurality of sub-pixels emitting each ofthe color lights. For example, the pixel 135 may include a firstsub-pixel 1351 emitting the first color light, a second sub-pixel 1352emitting the second color light, and a third sub-pixel 1353 emitting thethird color light. Each of the first sub-pixel 1351, the secondsub-pixel 1352, and the third sub-pixel 1353 may be separatelyelectrically driven.

FIG. 2 is a plan view of a micro-LED display apparatus 200 according toan example embodiment, and FIG. 3A is a cross-sectional view of themicro-LED display apparatus 200 of FIG. 2 , taken along line A-A. FIG. 2illustrates one sub-pixel of the micro-LED display apparatus 200according to an example embodiment.

Referring to FIGS. 2 and 3A, the micro-LED display apparatus 200 mayinclude a driving circuit substrate 210, a first electrode 220 formed onthe driving circuit substrate 210, at least one micro-LED 230 formed onthe first electrode 220, an insulating layer 235 formed to cover the atleast one micro-LED 230, and a second electrode 250 formed on theinsulating layer 235.

The driving circuit substrate 210 may include a driving circuit 211configured to drive the micro-LED 230. The driving circuit 211 mayinclude, for example, at least one transistor and at least onecapacitor. The driving circuit 211 may include, for example, a switchingtransistor, a driving transistor, and a capacitor. However, the drivingcircuit 211 is not limited thereto. The driving circuit 211 may includeone transistor and one capacitor. The driving circuit substrate 210 mayinclude, for example, a complementary metal-oxide-semiconductor (CMOS)backplane. However, the driving circuit substrate 210 is not limitedthereto.

The first electrode 220 may include, for example, a p-type electrode.

The micro-LED 230 may include, for example, a p-type semiconductor layer2301, an active layer 2302, and an n-type semiconductor layer 2303. Thep-type semiconductor layer 2301 may include a p-type GaN layer, and then-type semiconductor layer 2303 may include, for example, an n-type GaNlayer. The active layer 2302 may include, for example, a quantum-wellstructure or a multi-quantum-well structure. However, the micro-LED 230is not limited thereto.

An electrode pad 225 may further be formed between the first electrode220 and the micro-LED 230.

The insulating layer 235 may be formed to cover the micro-LED 230. Theinsulating layer 235 may have a greater thickness than the micro-LED230. The insulating layer 235 may include an inorganic insulating layerand/or an organic insulating layer. For example, the inorganicinsulating layer may include at least one of silicon oxide (SiO₂),aluminum oxide (Al₂O₃), hafnium oxide (HfO₂), and silicon nitride(Si₃N₄), and the organic insulating layer may include at least one ofacrylic resins, polystyrene, polymethylmethacrylate (PMMA),polyacrylonitrile (PAN), siloxane series resins, and epoxy resins. A viapattern 238 may be formed in the insulating layer 235. The via pattern238 may have a depth D to expose the micro-LED 230. For example, the viapattern 238 may have the depth D corresponding to a difference between aheight of the insulating layer 235 and a height of the micro-LED 230.For example, the via pattern 238 may have the depth D corresponding to adistance between an upper surface of the insulating layer 235 and anupper surface of the n-type semiconductor layer 2303 of the micro-LED230. The via pattern 238 may have various shapes. For example, the viapattern 238 may include a plurality of grooves arranged in theinsulating layer 235 at a predetermined interval. Also, electricalcontacts 240 may be provided in the via pattern 238. The electricalcontact 240 may include a conductive material. The electrical contact240 may have a structure which is defined by the via pattern 238. Thevia pattern 238 may have a pitch P that is less than a width W of themicro-LED 230. Also, the electrical contact 240 may have the pitch Pthat is less than the width W of the micro-LED 230. The electricalcontacts 240 may be arranged at a regular pitch. However, the electricalcontacts 240 may also be irregularly arranged. When the electricalcontacts 240 are irregularly arranged, a maximum distance betweenadjacent electrical contacts 240 may be less than the width W of themicro-LED 230. FIG. 2 illustrates an example in which the electricalcontacts 240 are arranged as dotted patterns.

The micro-LED 230 may have, for example, the width W, which is greaterthan about 0 and equal to or less than about 200 μm. The micro-LED 230may have, for example, the width W, which is greater than about 0 andequal to or less than about 100 μm. Alternatively, the micro-LED 230 mayhave, for example, the width W, which is greater than about 0 and equalto or less than about 1 μm. Here, the width W of the micro-LED 230 maybe a maximum cross-sectional width of the micro-LED 230. Here, thecross-sectional direction may be a direction perpendicular to adirection in which light is emitted.

When the electrical contacts 240 are arranged as described above, themicro-LEDs 230 may always contact the electrical contacts 240, even whenthe micro-LEDs 230 are irregularly arranged in a sub-pixel at anirregular interval. Also, when the micro-LEDs are transferred, there maybe cases in which the micro-LEDs are not provided or missing. In FIG.3A, a portion 232 may be an area where a micro-LED is not provided inthe sub-pixel. According to the example embodiment, the electricalcontact 240 has the thickness D corresponding to the difference betweenthe height of the micro-LED 230 and the height of the insulating layer235, and thus, a short-circuit may be prevented due to a step height,even when the micro-LED 230 is not provided. Thus, even when themicro-LED 230 is not provided, malfunctioning of the micro-LED displayapparatus 200 may be prevented. Also, the plurality of micro-LEDs 230are provided in the sub-pixel, and thus, a repair operation may not beneeded even when one or more of the micro-LEDs 230 is not provided.

The via pattern 238 may be provided for each sub-pixel. Alternatively,each sub-pixel may include a plurality of via patterns 238.

The second electrode 250 may be coupled to the electrical contacts 240.The second electrode 250 may be coupled to the electrical contacts 240such that the second electrode 250 contacts all of the electricalcontacts 240. The electrical contacts 240 and the second electrode 250may include different materials from each other. Alternatively, theelectrical contacts 240 and the second electrode 250 may include thesame material as each other.

In the micro-LED display apparatus 200 according to an exampleembodiment, one sub-pixel may include a plurality of the firstelectrodes 220, and the plurality of micro-LEDs 230 may be arranged ineach of the plurality of first electrodes 220. Also, the secondelectrode 250 may be provided to correspond to the first electrode 220.However, the second electrode 250 is not limited thereto. The secondelectrode 250 may be provided to entirely correspond to one sub-pixel.

According to the example embodiment, the micro-LED 230 may emitdifferent color light for each sub-pixel. In this case, a color filterconfigured to filter the color light from the micro-LED 230 may furtherbe provided. However, the micro-LED 230 may radiate the same color lightfor each sub-pixel.

FIG. 3B illustrates an example in which a via pattern 238A includes onegroove. In FIG. 3B, the components indicated by using the same referencenumerals as FIG. 3A have substantially the same structures andconfigurations as FIG. 3A, and thus, their detailed descriptions will beomitted here.

FIG. 3B illustrates the example in which the via pattern 238A includesone groove that is configured to cover the micro-LED 230 provided in onesub-pixel. An electrical contact 240A may be formed in the via pattern238A. The electrical contact 240A may include a conductive material. Thevia pattern 238A may have a depth D corresponding to a differencebetween a height of the insulating layer 235 and a height of themicro-LED 230. In this case, the via pattern 238A may cover mostportions of the sub-pixel, and thus, wherever the micro-LED 230 islocated, the electrical contact 240A and the micro-LED 230 may contacteach other.

FIG. 4 illustrates an example in which the micro-LED 230 radiates thesame color light for each sub-pixel.

FIG. 4 is a cross-sectional view of a micro-LED display apparatus 200Acorresponding to the micro-LED display apparatus 200 of FIG. 1 , takenalong line I-I. The micro-LED display apparatus 200A may include a firstsub-pixel 1351, a second sub-pixel 1352, and a third sub-pixel 1353.Here, the components indicated by using the same reference numerals asFIGS. 3A and 3B have substantially the same structures andconfigurations as FIGS. 3A and 3B, and thus, their detailed descriptionswill be omitted here.

The micro-LED display apparatus 200A may further include, for example,partition walls 270 on the insulating layer 235, and a color conversionlayer 260 between the partition walls 270. The partition walls 270 maybe arranged at a predetermined interval. The color conversion layer 260may be configured to convert a color of the light emitted from themicro-LED 230. The micro-LED 230 may emit first color light, forexample, blue light. However, embodiments are not limited thereto. Themicro-LED 230 may emit light of other wavelengths to excite the colorconversion layer 260.

The color conversion layer 260 may include a first color conversionlayer 261 configured to transmit light from the micro-LED 230, a secondcolor conversion layer 262 configured to convert light from themicro-LED 230 into second color light, and a third color conversionlayer 263 configured to convert light from the micro-LED 230 into thirdcolor light. The second color light may include, for example, greenlight, and the third color light may include, for example, red light.

The first color conversion layer 261 may include, for example, resinsthrough which the light from the micro-LED 230 is transmitted. Thesecond color conversion layer 262 may emit the green light using theblue light emitted from the micro-LED 230. The second color conversionlayer 262 may include quantum dots (QD) of predetermined sizes, whichare excited by the blue light and emit the green light. The QDs may havea core-shell structure having a core unit and a shell unit, or may havea particle structure having no shell. The core-shell structure mayinclude a single-shell structure or a multi-shell structure. Themulti-shell structure may include, for example, a double-shellstructure.

The QDs may include, for example, at least one of groups II-VI-basedsemiconductors, groups III-V-based semiconductors, groups IV-VI-basedsemiconductors, groups IV-based semiconductors, and a graphene QD. TheQDs may include, for example, at least one of cadmium (Cd), selenium(Se), zinc (Zn), sulfur (S), and indium phosphide (InP), but is notlimited thereto. Each QD may have a diameter that is equal to or lessthan about dozens of nms. For example, each QD may have a diameter thatis equal to or less than about 10 nm.

Alternatively, the second color conversion layer 262 may include aphosphor excited by the blue light emitted from the micro-LED 230 andemitting the green light.

The third color conversion layer 263 may emit the red light by changingthe blue light emitted from the micro-LED 230 into the red light. Thethird color conversion layer 263 may include QDs of predetermined sizes,which are excited by the blue light and emit the red light.Alternatively, the third color conversion layer 263 may include aphosphor excited by the blue light emitted from the micro-LED 230 andemitting the red light.

FIGS. 5 through 8 are enlarged views of various examples in whichmicro-LEDs 315, 325, 335, and 345 are arranged in a region correspondingto one sub-pixel.

Referring to FIG. 5 , two first electrodes 312 may be provided in aregion 310 corresponding to a sub-pixel, and the micro-LED 315 may beprovided in each of the two first electrodes 312. The micro-LED 315 mayhave, for example, a circular cross-section. However, the micro-LED 315is not limited thereto, and may have cross-sections of various shapes,such as a quadrangular cross-section, a pentagonal cross-section, etc.The micro-LED 315 may have, for example, a vertical chip structure.

According to the example embodiment, the two first electrodes 312 may bearranged in a diagonal direction in the region 310. However, thelocation of the two first electrodes 312 is not limited thereto and maybe variously modified. The arrangement of the first electrodes 312 mayhave a corresponding relationship with a transferring location of themicro-LED 315.

Referring to FIG. 6 , two first electrodes 322 may be provided in aregion 320 corresponding to a sub-pixel, and a plurality of micro-LEDs325 may be provided in each of the two first electrodes 322. Each of thetwo first electrodes 322 may have a size to accommodate the plurality ofmicro-LEDs 325. Here, the two first electrodes 322 may be arranged in adiagonal direction in the region 320. However, the location of the twofirst electrodes 322 is not limited thereto and may be variouslymodified.

Referring to FIG. 7 , one first electrode 332 may be provided in aregion 330 corresponding to a sub-pixel, and a plurality of micro-LEDs335 may be provided in the first electrode 332.

Referring to FIG. 8 , eight first electrodes 342 may be provided in aregion 340 corresponding to a sub-pixel. A micro-LED 345 may be providedin each of the eight first electrodes 342. When there are the pluralityof first electrodes 342 in the region 340 corresponding to the sub-pixelas described above, even when the micro-LEDs of one or more of theplurality of first electrodes 342 are not provided, the pixel mayoperate normally. Thus, a pixel defect rate may be decreased, and arepair operation may be reduced. A portion 347 indicates an areacorresponding to a missing micro-LED.

FIGS. 9 through 12 illustrate examples of various patterns of theelectrical contacts 240 and 240A described with reference to FIGS. 2, 3Aand 3B.

Referring to FIG. 9 , an electrical contact 415 may include dottedpatterns connected to a second electrode 410. A pitch P of the dottedpatterns may be less than the width W of the micro-LED 230 (see FIG.3A). When the dotted patterns are irregularly arranged, a maximum pitchP between the dotted patterns may be less than the width W of themicro-LED 230.

Referring to FIG. 10 , an electrical contact 425 may include stripepatterns connected to a second electrode 420. A pitch P of the stripepatterns may be less than the width W of the micro-LED 230. Referring toFIG. 11 , an electrical contact 435 may include grid patterns connectedto a second electrode 430. A pitch P of the grid patterns may be lessthan the width W of the micro-LED 230.

Referring to FIG. 12 , an electrical contact 445 may include concentriccircular patterns connected to a second electrode 440. A pitch P of theconcentric circular patterns may be less than the width W of themicro-LED 230. The electrical contact 445 may be provided throughout aregion in which the electrical contact 445 may cover all of thecorresponding micro-LEDs 230.

The patterns of the electrical contacts 415 through 445 are describedwith reference to FIGS. 9 through 12 . Because the electrical contact isdefined by the via pattern, the patterns of the electrical contacts 415through 445 described above may be similarly applied to the via patterns238 and 238A (see FIGS. 3A and 3B).

FIGS. 13 through 15 illustrate examples of various layout structures offirst electrodes 512, 522, and 532 and second electrodes 515, 525, and535.

Referring to FIG. 13 , eight first electrodes 512 may be provided in asub-pixel 510. One micro-LED 518 may be provided in each of the eightfirst electrodes 512, and one second electrode 515 may be provided tocorrespond to each of the eight first electrodes 512. Also, anelectrical contact 517 connected between the second electrode 515 andthe micro-LED 518 may be provided. An interconnection line 519 may beconnected to each of the eight first electrodes 512. In FIG. 13 , onemicro-LED may not be provided, and the electrical contact 517 may bespaced apart from the first electrode 512 in a location in which themicro-LED is not provided. Thus, a short-circuit may be prevented.

Referring to FIG. 14 , eight first electrodes 522 may be provided in asub-pixel 520. One micro-LED 528 may be provided in each of the eightfirst electrodes 522, and one second electrode 525 may be provided tocorrespond to four first electrodes 522. Also, an electrical contact 527connected between the second electrode 525 and the micro-LED 528 may beprovided. For example, the electrical contact 527 may have stripepatterns. The electrical contacts 527 may be arranged to have a pitchthat is less than a width of the micro-LEDs 528, and thus, even when themicro-LEDs 528 are irregularly arranged, the micro-LEDs 528 may beelectrically connected to the second electrode 525 from any location.When a plurality of micro-LEDs are arranged in one sub-pixel, even whenone or more micro-LEDs are not provided or defects occur to one or moremicro-LEDs, a normal operation may become possible via other normalmicro-LEDs. Thus, a repair operation may not be required.

Referring to FIG. 15 , two first electrodes 532 may be provided in asub-pixel 530. A plurality of micro-LEDs 538 may be provided in each ofthe two first electrodes 532, and one second electrode 535 may beprovided to correspond to the two first electrodes 532. In this case,one second electrode 535 may be provided in the sub-pixel 530. Also, anelectrical contact 537 connected between the second electrode 535 andthe micro-LED 538 may be provided. For example, the electrical contact537 may be provided in grid patterns.

As described above, the first electrode and the second electrode mayhave a 1-on-1 correspondence structure or an n-on-1 correspondencestructure, where n is greater than 1.

Next, a method of manufacturing a micro-LED display apparatus will bedescribed according to an example embodiment.

With respect to the method of manufacturing the micro-LED displayapparatus, referring to FIG. 16 , a transfer substrate 600 including aplurality of grooves 615 may be prepared. FIG. 16 illustrates onesub-pixel. FIG. 17 is a cross-sectional view of the sub-pixel of FIG. 16, taken along line B-B. The transfer substrate 600 may include a singlelayer or multiple layers. Each of the plurality of grooves 615 may beprovided to include at least one micro-LED 620. The micro-LED 620 may betransferred onto the plurality of grooves 615. As a method oftransferring the micro-LED 620, a dry transfer method or a wet transfermethod may be used.

FIG. 18 illustrates an example flowchart of the wet transfer method. Thewet transfer method may include preparing the transfer substrate 600including the plurality of grooves 615 (S101), supplying a liquid to theplurality of grooves 615 of the transfer substrate 600 (S102), supplyingthe plurality of micro-LEDs 620 to the transfer substrate 600 (S103),and absorbing the liquid by scanning the transfer substrate 600 via anabsorber capable of absorbing a liquid (S104).

The supplying of the liquid may include, for example, at least one ofspraying, dispensing, inkjet dot spreading, and a method of spilling aliquid onto a transfer substrate. The liquid may include, for example,at least one from the group consisting of water, ethanol, alcohol,polyol, ketone, halocarbon, acetone, a flux, and a solvent. The scanningof the transfer substrate 600 via the absorber may include having theabsorber contact and slide through the transfer substrate 600.

The plurality of micro-LEDs 620 may be directly spread on the transfersubstrate 600 without the liquid or may be supplied to the transfersubstrate 600 by using other materials than the liquid. Alternatively,other various methods may be used to transfer the micro-LEDs 620 to thetransfer substrate 600. For example, the micro-LEDs 620 may be providedto the transfer substrate 600 while contained in a suspension. In thiscase, the supplying of the micro-LEDs 620 to the transfer substrate 600may include various methods, such as spraying, dispensing, inkjet dotspreading, a method of spilling a suspension onto a transfer substrate,etc. The methods of supplying the micro-LEDs 620 to the transfersubstrate 600 are not limited thereto and may be variously modified. Theliquid may be supplied to the grooves 615 such that the amount of liquidproperly fits the grooves 615 or such that the liquid spills over thegrooves 615. The amount of liquid that is supplied may be variouslymodified.

The absorber for absorbing the liquid may include various types ofmaterials capable of absorbing the liquid, and a shape or a structure ofthe absorber is not limited to particular types. The absorber mayinclude, for example, fabric, a tissue, a polyester fiber, paper, awiper, or the like. The absorber may be independently used without anauxiliary device or may be used along with an auxiliary device accordingto necessity.

An electrode pad 625 may be located on an upper surface of the micro-LED620, the upper surface facing an opening of the grooves 615. At leastone micro-LED 620 may be provided in the grooves 615. The micro-LEDs 620may be irregularly arranged. The grooves 615 may have a greater sizethan the micro-LEDs 620. Depending on the size of the grooves 615, thenumber of micro-LEDs 620 transferred onto the grooves 615 may vary.

For example, the micro-LEDs 620 may have a size that is equal to or lessthan about 200 μm. Here, the size may indicate a maximum cross-sectionaldiameter of the micro-LED 620. Here, the cross-sectional direction mayindicate a direction perpendicular to a direction in which light isemitted from the micro-LEDs 620. The micro-LEDs 620 may havecross-sections of various shapes, such as a triangular cross-section, aquadrangular cross-section, a circular cross-section, etc. Sizes of thegrooves 615 may be determined, for example, according to the desirednumber of micro-LEDs 620. The grooves 615 may have various shapes. Forexample, the grooves 615 may have a triangular cross-section, aquadrangular cross-section, a circular cross-section, or the like. Twogrooves 615 may be provided in one sub-pixel, and one micro-LED 620 maybe provided in each groove 615. Alternatively, two grooves 615 may beprovided in one sub-pixel, and a plurality of micro-LEDs 620 may beprovided in each groove 615. Alternatively, one groove 615 may beprovided in one sub-pixel, and a plurality of micro-LEDs 620 may beprovided in the groove 615. Alternatively, eight grooves 615 may beprovided in one sub-pixel, and one micro-LED 620 may be provided in eachof the eight grooves 615. However, a number of the grooves 615 and themicro-LEDs 620 provided are not limited thereto, and embodiments mayhave various other arrangement structures. The micro-LEDs 620 may have,for example, a vertical electrode structure.

Referring to FIG. 19 , a first electrode 640 may be formed on thedriving circuit substrate 630. FIG. 20 is a cross-sectional view of thedriving circuit substrate 630 of FIG. 19 , taken along line C-C. Thedriving circuit substrate 630 may include, for example, at least onetransistor and at least one capacitor. The at least one transistor mayinclude, for example, a switching transistor and a driving transistor.The first electrode 640 may be provided to correspond to the groove 615of the transfer substrate 600 illustrated in FIG. 16 . However, thefirst electrode 640 is not limited thereto and may be variouslymodified. The first electrode 640 and another first electrode 640 may beconnected to each other via an interconnect line 641. The firstelectrode 640 may have various shapes, such as a circular shape, aquadrangular shape, etc.

Referring to FIG. 21 , the driving circuit substrate 630 illustrated inFIG. 19 may correspond to the transfer substrate 600 illustrated in FIG.16 , and thus, the micro-LED 620 may be transferred from the transfersubstrate 600 to the driving circuit substrate 630 to contact the firstelectrode 640. The micro-LED 620 may be bonded to the first electrode640.

FIG. 22 is a cross-sectional view of FIG. 21 , taken along line D-D.Referring to FIG. 22 , the electrode pad 625 may be provided between thefirst electrode 640 and the micro-LED 620. FIG. 21 illustrates thatthree micro-LEDs 620 are arranged in one first electrode 640. However,the example of FIG. 21 illustrates that one of the four micro-LEDs 620arranged in the first electrode 640 is not provided. In FIG. 22 , aportion 622 indicates an area of the missing micro-LED. According to theexample embodiment, a normal operation may be performed without a repairoperation performed on the missing micro-LED.

Referring to FIG. 23 , an insulating layer 650 may be deposited on thedriving circuit substrate 630. The insulating layer 650 may be providedto cover the micro-LED 620. The insulating layer 650 may have a greaterthickness than the micro-LED 620. For example, a predetermined thicknessbetween an upper surface of the insulating layer 650 and an uppersurface of the micro-LED 620 may be defined. A via pattern 660 may beformed in the insulating layer 650. The via pattern 660 may have a depthd corresponding to a distance between the upper surface of theinsulating layer 650 and the upper surface of the micro-LED 620. The viapattern 660 may have the depth d to expose the micro-LED 620. The depthd of the via pattern 660 may be selectively formed by adjusting an etchduration time or using a resolution and a critical dimension of aphotosensitive material.

Referring to FIG. 24 , electrical contacts 670 may be formed in the viapattern 660. The electrical contacts 670 may be defined by the viapattern 660. For example, the via pattern 660 may have various patterns,such as dotted patterns, stripe patterns, grid patterns, or concentricpatterns. For example, the electrical contacts 670 may have variouspatterns, such as dotted patterns, stripe patterns, grid patterns, orconcentric patterns. The electrical contacts 670 may have the thicknesscorresponding to the distance between the upper surface of theinsulating layer 650 and the upper surface of the micro-LED 620. Also,the electrical contacts 670 may include the patterns having a pitch thatis less than a width of the micro-LED 620, as described above withreference to FIGS. 9 through 12 .

A second electrode 675 may be formed on the electrical contacts 670 andthe insulating layer 650. The second electrode 675 may include, forexample, a transparent electrode, such as indium tin oxide (ITO), indiumzinc oxide (IZO), ITO/Ag/ITO, etc. When the electrical contacts 670 havethe thickness and the pitch as described above, regardless of thelocation of the micro-LEDs 620, the electrical contacts 670 and themicro-LEDs 620 may be connected to each other, and a short-circuit maybe prevented at a location of the missing micro-LED 622. Thus,malfunctioning may be prevented without a repair operation, and normaloperations may become possible via the micro-LEDs 620 that are provided.

Referring to FIG. 25 , an interconnect line 680 connected to the secondelectrode 675 may be formed.

According to the method of manufacturing the micro-LED display apparatusaccording to an example embodiment described above, a micro-LED may betransferred to a large area at high speed via a self-assembly method,and a plurality of micro-LEDs may be transferred to a sub-pixel, andthus, a defect rate may be reduced. Also, based on the selective viapattern structure, from a region in which the micro-LEDs are providedand a region in which the micro-LEDs are not provided, only the regionincluding the micro-LEDs may be electrically connected. Based on theselective via pattern structure, process margins reflecting ashort-circuit defect may be reduced, and thus, a degree of freedom of aregion in which a first electrode and a second electrode overlap eachother may be increased to increase align margins of a bonding process.Thus, even when the size of the micro-LEDs decreases, a process yieldrate may be increased.

The micro-LED display apparatuses 100, 200, 200A according to exampleembodiments may be applied to various electronic devices, such as amicro-LED television (TV), an liquid crystal display apparatus, a mobiledevice, a vehicle display apparatus, augmented reality (AR) glasses,virtual reality (VR) glasses, etc.

FIG. 26 is a block diagram of an electronic device 8201 including themicro-LED display apparatuses 100, 200, and 200A according to an exampleembodiment.

Referring to FIG. 26 , the electronic device 8201 may be provided in anetwork environment 8200. In the network environment 8200, theelectronic device 8201 may communicate with another electronic device8202 through a first network 8298 (a short-range wireless communicationnetwork, etc.) or communicate with another electronic device 8204 and/ora server 8208 through a second network 8299 (a remote wirelesscommunication network, etc.). The electronic device 8201 may communicatewith the electronic device 8204 through the server 8208. The electronicdevice 8201 may include a processor 8220, a memory 8230, an input device8250, a sound output device 8255, a display apparatus 8260, an audiomodule 8270, a sensor module 8276, an interface 8277, a haptic module8279, a camera module 8280, a power management module 8288, a battery8289, a communication module 8290, a subscriber identification module8296, and/or an antenna module 8297. The electronic device 8201 may omitone or more of the components or may further include other components.One or more of the components may be realized as an integrated circuit.For example, the sensor module 8276 (a fingerprint sensor, an irissensor, an illumination sensor, etc.) may be embedded in the displayapparatus 8260 (a display, etc.).

The processor 8220 may be configured to execute software (a program8240, etc.) to control one or more components (hardware or softwarecomponents) of the electronic device 8201, the components beingconnected to the processor 8220, and to perform various data processingor calculations. As part of the data processing or calculations, theprocessor 8220 may be configured to load a command and/or data receivedfrom other components (the sensor module 8276, the communication module8290, etc.) into the volatile memory 8232, process the command and/orthe data stored in a volatile memory 8232, and store resultant data in anonvolatile memory 8234. The processor 8220 may include a main processor8221 (a central processing unit (CPU), an application processor (AP),etc.) and an auxiliary processor 8223 (a graphics processing unit (GPU),an image signal processor, a sensor hub processor, a communicationprocessor, etc.) which may independently operate or operate with themain processor 8221. The auxiliary processor 8223 may use less powerthan the main processor 8221 and may perform specialized functions.

When the main processor 8221 is in an inactive state (a sleep state),the auxiliary processor 8223 may take charge of an operation ofcontrolling functions and/or states related to one or more components(the display apparatus 8260, the sensor module 8276, the communicationmodule 8290, etc.) from among the components of the electronic device8201, or when the main processor 8221 is in an active state (anapplication execution state), the auxiliary processor 8223 may performthe same operation along with the main processor 8221. The auxiliaryprocessor 8223 (the image signal processor, the communication processor,etc.) may be realized as part of other functionally-related components(the camera module 8280, the communication module 8290, etc.).

The memory 8230 may store various data required by the components (theprocessor 8220, the sensor module 8276, etc.) of the electronic device8201. The data may include, for example, software (the program 8240,etc.), input data and/or output data of a command related to thesoftware. The memory 8230 may include the volatile memory 8232 and/orthe nonvolatile memory 8234. The nonvolatile memory 8234 may comprise anembedded memory 8236 and/or an external memory 8238.

The program 8240 may be stored in the memory 8230 as software, and mayinclude an operating system 8242, middleware 8244, and/or an application8246.

The input device 8250 may receive a command and/or data to be used bythe components (the processor 8220, etc.) of the electronic device 8201from the outside of the electronic device 8201. The input device 8250may include a remote controller, a microphone, a mouse, a keyboard,and/or a digital pen (a stylus pen, etc.).

The sound output device 8255 may output a sound signal to the outside ofthe electronic device 8201. The sound output device 8255 may include aspeaker and/or a receiver. The speaker may be used for a generalpurpose, such as multimedia playing or recording playing, and thereceiver may be used to receive an incoming call. The receiver may becoupled to the speaker as part of the speaker or may be realized as aseparate device.

The display apparatus 8260 may visually provide information to theoutside of the electronic device 8201. The display apparatus 8260 mayinclude a display, a hologram device, or a controlling circuit forcontrolling a projector and a corresponding device. The displayapparatus 8260 may implement the micro-LED display apparatuses 100, 200,and 200A described with reference to FIGS. 1 through 25 . The displayapparatus 8260 may include touch circuitry configured to sense a touchoperation and/or sensor circuitry (a pressure sensor, etc.) configuredto measure an intensity of a force generated by the touch operation.

The audio module 8270 may convert sound into an electrical signal or anelectrical signal into sound. The audio module 8270 may obtain sound viathe input device 8250 or may output sound via the sound output device8255 and/or a speaker and/or a headphone of an electronic device (theelectronic device 8202, etc.) directly or wirelessly connected to theelectronic device 8201.

The sensor module 8276 may sense an operation state (power, temperature,etc.) of the electronic device 8201 or an external environmental state(a user state, etc.) and generate electrical signals and/or data valuescorresponding to the sensed state. The sensor module 8276 may include agesture sensor, a gyro-sensor, an atmospheric sensor, a magnetic sensor,an acceleration sensor, a grip sensor, a proximity sensor, a colorsensor, an infrared (IR) sensor, a biometric sensor, a temperaturesensor, a humidity sensor, and/or an illumination sensor.

The interface 8277 may support one or more designated protocols to beused for the electronic device 8201 to be directly or wirelesslyconnected to another electronic device (the electronic device 8202,etc.). The interface 8277 may include a high-definition multimediainterface (HDMI) interface, a universal serial bus (USB) interface, anSD card interface, and/or an audio interface.

A connection terminal 8278 may include a connector, through which theelectronic device 8201 may be physically connected to another electronicdevice (the electronic device 8202, etc.). The connection terminal 8278may include an HDMI connector, a USB connector, an SD card connector,and/or an audio connector (a headphone connector, etc.).

An haptic module 8279 may convert an electrical signal into a mechanicalstimulus (vibration, motion, etc.) or an electrical stimulus which isrecognizable to a user via haptic or motion sensation. The haptic module8279 may include a motor, a piezoelectric device, and/or an electricalstimulus device.

The camera module 8280 may capture a still image and a video. The cameramodule 8280 may include a lens assembly including one or more lenses,image sensors, image signal processors, and/or flashes. The lensassemblies included in the camera module 8280 may collect light emittedfrom an object, an image of which is to be captured.

The power management module 8288 may manage power supplied to theelectronic device 8201. The power management module 8388 may be realizedas part of a power management integrated circuit (PMIC).

The battery 8289 may supply power to the components of the electronicdevice 8201. The battery 8289 may include a non-rechargeable primarybattery, rechargeable secondary battery, and/or a fuel battery.

The communication module 8290 may support establishment of direct(wired) communication channels and/or wireless communication channelsbetween the electronic device 8201 and other electronic devices (theelectronic device 8202, the electronic device 8204, the server 8208,etc.) and communication performance through the establishedcommunication channels. The communication module 8290 may include one ormore communication processors separately operating from the processor8220 (an application processor, etc.) and supporting directcommunication and/or wireless communication. The communication module8290 may include a wireless communication module 8292 (a cellularcommunication module, a short-range wireless communication module, aglobal navigation satellite system (GNSS) communication module), and/ora wired communication module 8294 (a local area network (LAN)communication module, a power line communication module, etc.). Fromthese communication modules, a corresponding communication module maycommunicate with other electronic devices through a first network 8298(a short-range wireless communication network, such as Bluetooth, Wifidirect, or infrared data association (IrDa)) or a second network 8299 (aremote communication network, such as a cellular network, the Internet,or a computer network (LAN, WAN, etc.)). Various types of communicationmodules described above may be integrated as a single component (asingle chip, etc.) or realized as a plurality of components (a pluralityof chips). The wireless communication module 8292 may identify andauthenticate the electronic device 8201 within the first network 8298and/or the second network 8299 by using subscriber information(international mobile subscriber identification (IMSI), etc.) stored inthe subscriber identification module 8296.

The antenna module 8297 may transmit a signal and/or power to theoutside (other electronic devices, etc.) or receive the same from theoutside. The antenna may include an emitter including a conductivepattern formed on a substrate (a printed circuit board (PCB), etc.). Theantenna module 8297 may include an antenna or a plurality of antennas.When the antenna module 8297 includes a plurality of antennas, anappropriate antenna which is suitable for a communication method used inthe communication networks, such as the first network 8298 and/or thesecond network 8299, may be selected. Through the selected antenna,signals and/or power may be transmitted or received between thecommunication module 8290 and other electronic devices. In addition tothe antenna, another component (a radio frequency integrated circuit(RFIC), etc.) may be included in the antenna module 8297.

One or more of the components of the electronic device 8201 may beconnected to one another and exchange signals (commands, data, etc.)with one another, through communication methods performed amongperipheral devices (a bus, general purpose input and output (GPIO), aserial peripheral interface (SPI), a mobile industry processor interface(MIPI), etc.).

The command or the data may be transmitted or received between theelectronic device 8201 and another external electronic device 8204through the server 8208 connected to the second network 8299. Otherelectronic devices 8202 and 8204 may be electronic devices that arehomogeneous or heterogeneous types with respect to the electronic device8201. All or part of operations performed in the electronic device 8201may be performed by one or more of the other electronic devices 8202,8204, and 8208. For example, when the electronic device 8201 has toperform a function or a service, instead of directly performing thefunction or the service, the one or more other electronic devices may berequested to perform part or all of the function or the service. The oneor more other electronic devices receiving the request may perform anadditional function or service related to the request and may transmit aresult of the execution to the electronic device 8201. To this end,cloud computing, distribution computing, and/or client-server computingtechniques may be used.

FIG. 27 illustrates an example in which a micro-LED display apparatusaccording to an example embodiment is applied to a mobile device 9100.The mobile device 9100 may include a micro-LED display apparatus 9110according to an example embodiment. The micro-LED display apparatus 9110may include the micro-LED display apparatuses 100, 200, and 200Adescribed with reference to FIGS. 1 through 25 . The micro-LED displayapparatus 9110 may have a foldable structure. For example, the micro-LEDdisplay apparatus 9110 may include a multi-foldable display apparatus.Here, the mobile device 9100 is illustrated as including a foldablemicro-LED display apparatus. However, the mobile device 9100 may alsoinclude a flat display apparatus.

FIG. 28 illustrates an example in which a micro-LED display apparatusaccording to an example embodiment is applied to a vehicle. Themicro-LED display apparatus may be applied to a vehicle head up displayapparatus 9200. The vehicle head up display apparatus 9200 may include adisplay 9210 provided in a region of the vehicle and at least oneoptical path-change member 9220 configured to convert an optical pathfor a driver to watch an image generated by the display 9210.

FIG. 29 illustrates an example in which a micro-LED display apparatusaccording to an example embodiment is applied to augmented reality (AR)glasses 9300 or virtual reality (VR) glasses. The AR glasses 9300 mayinclude a projection system 9310 configured to form an image and atleast one component 9320 configured to guide an image from theprojection system 9310 to the eye of a user. The projection system 9310may include the micro-LED display apparatuses 100, 200, and 200Adescribed with reference to FIGS. 1 through 25 .

FIG. 30 illustrates an example in which a micro-LED display apparatusaccording to an example embodiment is applied to signage 9400. Thesignage 9400 may be used for outdoor advertising using digitalinformation display and may control advertisement content through acommunication network. The signage 9400 may be realized for example bythe electronic device described with reference to FIG. 26 .

FIG. 31 illustrates an example in which a micro-LED display apparatusaccording to an example embodiment, is applied to a wearable display9500. The wearable display 9500 may include the display apparatusesdescribed with reference to FIGS. 1 through 25 or may be realized by theelectronic device 8201 described with reference to FIG. 26 .

Also, the micro-LED display apparatuses 100, 200, and 200A according toan example embodiment may be applied to various devices, such as arollable TV, a stretchable display, etc.

The micro-LED display apparatus according to an example embodiment mayinclude a micro-LED and reduce a repair rate. The micro-LED displayapparatus according to an example embodiment may include a plurality ofmicro-LEDs in one sub-pixel and, even when the micro-LEDs areirregularly arranged, may prevent electrical defects.

The method of manufacturing the micro-LED display apparatus according toan example embodiment may enable convenient manufacturing of themicro-LED display apparatus.

It should be understood that example embodiments described herein shouldbe considered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each exampleembodiment should typically be considered as available for other similarfeatures or aspects in other embodiments. While example embodiments havebeen described with reference to the figures, it will be understood bythose of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeas defined by the following claims.

What is claimed is:
 1. A micro-light-emitting diode (LED) displayapparatus including a plurality of pixels, the micro-LED displayapparatus comprising: a driving circuit substrate; a first electrodeprovided on the driving circuit substrate; one or moremicro-light-emitting diodes (LEDs) provided on the first electrode; aninsulating layer provided on the one or more micro-LEDs; a via patternprovided in the insulating layer; electrical contacts provided in thevia pattern; and a second electrode provided on the electrical contacts,wherein the via pattern exposes a portion of the one or more micro-LEDs,wherein each of the plurality of pixels comprises a plurality ofsub-pixels, and wherein the micro-LEDs are arranged in each of theplurality of sub-pixels at an irregular interval.
 2. Themicro-light-emitting diode (LED) display apparatus of claim 1, wherein athickness of the insulating layer is greater than a thickness of the oneor more micro-LEDs.
 3. The micro-light-emitting diode (LED) displayapparatus of claim 1, wherein a thickness of each of the electricalcontacts corresponds to a distance between an upper surface of theinsulating layer and an upper surface of the one or more micro-LEDs. 4.The micro-light-emitting diode (LED) display apparatus of claim 1,wherein a pitch of the electrical contacts is less than a width of eachof the one or more micro-LEDs.
 5. The micro-light-emitting diode (LED)display apparatus of claim 1, wherein each of the plurality of pixelscomprises a plurality of sub-pixels, and wherein the via pattern isprovided on each of the plurality of sub-pixels.
 6. Themicro-light-emitting diode (LED) display apparatus of claim 1, whereineach of the plurality of pixels comprises a plurality of sub-pixels, andwherein the one or more micro-LEDs are provided on each of the pluralityof sub-pixels.
 7. The micro-light-emitting diode (LED) display apparatusof claim 6, wherein the one or more micro-LEDs are arranged in each ofthe plurality of sub-pixels at an irregular interval.
 8. Themicro-light-emitting diode (LED) display apparatus of claim 1, whereinthe one or more micro-LEDs are connected between the first electrode andthe second electrode.
 9. The micro-light-emitting diode (LED) displayapparatus of claim 1, wherein the electrical contacts are provided indotted patterns, stripe patterns, grid patterns, or concentric-circularpatterns.